text: Silyl enol ethers are used in many reactions resulting in alkylation, e.g., Mukaiyama aldol addition, Michael reactions, and Lewis-acid-catalyzed reactions with S1-reactive electrophiles (e.g., tertiary, allylic, or benzylic alkyl halides). Alkylation of silyl enol ethers is especially efficient with tertiary alkyl halides, which form stable carbocations in the presence of Lewis acids like Titanium tetrachloride| or Tin(IV) chloride|.